PLT 1 set forth below describes an electronic apparatus such as a mobile phone that delivers an air conduction sound and a bone conduction sound to a user. The PLT1 also describes that the air conduction sound is a sound that is delivered to the auditory nerve of the user when vibration of the air caused by vibration of an object reaches the eardrum through the ear canal and vibrates the eardrum. The PLT 1 further describes that a vibration sound is a sound that is delivered to the auditory nerve of the user via a part of a user's body (for example, the cartilage of the ear) in contact with the object being vibrating.
In the phone described in the PLT 1, a vibrator in the form of a short rectangular plate constituted by using a piezoelectric bimorph and a flexible material is attached to an outer surface of a housing via an elastic member. The PLT 1 also describes that, upon application of a voltage to the piezoelectric bimorph of the vibrator, a piezoelectric material stretches and contracts in a longitudinal direction causing the vibrator to vibrate in a bending manner and, when the user brings the vibrator into contact with the auricle, the air conduction sound and the vibration sound are delivered to the user.